When using the Rescue Ranger or frontier justice with the wrangler. standard wrench is still fairly anyway, it has a high crit raito and does fair damage, more than your shotgun often puts out. The southern hospitality can also dish out some serious bleed damage. But in reality, you want to put up your sentry as fast as possible more often than not, so you'd be using the jag (which is terrible for melee). So it really boils down to how you're playing Engineer. If you're playing combat engineer with the gunslinger or you're using the jag then best to stick with you guns and sentry. If you're going mostly stock weapons then mostly just for killing spies, and if you're feeling feisty or have poor combat-esque guns equiped then you can actually melee kill people while building, deploying, or away from your sentry. If you are a 'professional engineer' then you'll be able to adapt and get kills however you can anyway.

Crit chance increases with damage you or your sentry does. Your wrench already has a 15% crit chance, increase that and you'll find you crit a lot, enough to take out any class at full health that's not a Soldier (the chances of him having more than 185 health when you encounter him near a Sentry are small) or Heavy.

Melee combat mechanics are not to be relied on, particularly as for anybody who *isn't* a spy the attack 'fires' during the animation, not at the beginning, and as they rely on some non-intuitive mechanics and invisible collision hulls. Play Medieval to practice...

Did you ever think that he may just like hitting people with his wrench and its that simple?Like driving a classic muscle car ,its not good on gas,handling and braking is bad, and isn't as fast as a modern car but man its fun